mm: always inline __mk_vma_flags() and invoked functions

Be explicit about __mk_vma_flags() (which is used by the mk_vma_flags()
macro) always being inline, as we rely on the compiler to evaluate the
loop in this function and determine that it can replace the code with the
an equivalent constant value, e.g. that:

__mk_vma_flags(2, (const vma_flag_t []){ VMA_WRITE_BIT, VMA_EXEC_BIT });

Can be replaced with:

(1UL << VMA_WRITE_BIT) | (1UL << VMA_EXEC_BIT)

= (1UL << 1) | (1UL << 2) = 6

Most likely an 'inline' will suffice for this, but be explicit as we can
be.

Also update all of the functions __mk_vma_flags() ultimately invokes to be
always inline too.

Note that test_bitmap_const_eval() asserts that the relevant bitmap
functions result in build time constant values.

Additionally, vma_flag_set() operates on a vma_flags_t type, so it is
inconsistently named versus other VMA flags functions.

We only use vma_flag_set() in __mk_vma_flags() so we don't need to worry
about its new name being rather cumbersome, so rename it to
vma_flags_set_flag() to disambiguate it from vma_flags_set().

Also update the VMA test headers to reflect the changes.

Link: https://lkml.kernel.org/r/241f49c52074d436edbb9c6a6662a8dc142a8f43.1772704455.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chatre, Reinette <reinette.chatre@intel.com>
Cc: Chunhai Guo <guochunhai@vivo.com>
Cc: Damien Le Maol <dlemoal@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hongbo Li <lihongbo22@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naohiro Aota <naohiro.aota@wdc.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Sandeep Dhavale <dhavale@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yue Hu <zbestahu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 6 insertions, 4 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index f964e4050583..9dcdf13570fb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1030,21 +1030,23 @@ static inline bool vma_test_atomic_flag(struct vm_area_struct *vma, vma_flag_t b
 }
 
 /* Set an individual VMA flag in flags, non-atomically. */
-static inline void vma_flag_set(vma_flags_t *flags, vma_flag_t bit)
+static __always_inline void vma_flags_set_flag(vma_flags_t *flags,
+		vma_flag_t bit)
 {
 	unsigned long *bitmap = flags->__vma_flags;
 
 	__set_bit((__force int)bit, bitmap);
 }
 
-static inline vma_flags_t __mk_vma_flags(size_t count, const vma_flag_t *bits)
+static __always_inline vma_flags_t __mk_vma_flags(size_t count,
+		const vma_flag_t *bits)
 {
 	vma_flags_t flags;
 	int i;
 
 	vma_flags_clear_all(&flags);
 	for (i = 0; i < count; i++)
-		vma_flag_set(&flags, bits[i]);
+		vma_flags_set_flag(&flags, bits[i]);
 	return flags;
 }
 
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 7bc82a2b889f..f22aecb047b7 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -1056,7 +1056,7 @@ struct vm_area_struct {
 } __randomize_layout;
 
 /* Clears all bits in the VMA flags bitmap, non-atomically. */
-static inline void vma_flags_clear_all(vma_flags_t *flags)
+static __always_inline void vma_flags_clear_all(vma_flags_t *flags)
 {
 	bitmap_zero(flags->__vma_flags, NUM_VMA_FLAG_BITS);
 }